The present invention relates to a thermal management system for use in an aircraft. More particularly, the present invention relates to a thermal management system configured to distribute heating or cooling between a plurality of heat pump units.
A typical commercial aircraft includes at least several nonintegrated cooling systems configured to provide temperature control to various regions of the aircraft. For example, an aircraft cooling system primarily provides heating and cooling for the aircraft cabin area. In addition, a galley chiller system is dedicated to refrigerating the food carts in the galleys located throughout the aircraft. Since each system has a significant weight and power requirement, the overall efficiency of the aircraft is affected by these nonintegrated systems.
Typically, aircraft cooling systems are standalone vapor cycle units. The vapor cycle units generally include a compressor pumping a refrigerant to a condenser, which rejects heat from the compressed refrigerant to the surrounding environment. The refrigerant from the condenser is regulated through an expansion valve to an evaporator where the refrigerant expands to cool the fluid. The refrigerant within the evaporator absorbs heat from the surrounding environment. After absorbing heat, the refrigerant flows from the evaporator to the compressor where the cycle repeats. Since each vapor cycle unit is dedicated to one region of the aircraft, a typical aircraft requires many of these units to meet its cooling demands.
In other types of aircraft, one or more vapor cycle units are positioned at one centralized location in the aircraft rather than having separate units dedicated to providing temperature control to one specific region. These vapor cycle units cool the refrigerant, pump the refrigerant to various locations throughout the aircraft that require cooling, and then direct all of the refrigerant back to the centralized vapor unit location. Thus, all the cooling of the refrigerant is performed at one location. Since the cooling is performed at one centralized location, the vapor cycle units are typically large, heavy, and utilize a significant amount of refrigerant, thus increasing the weight of the aircraft and decreasing aircraft efficiency.
Thus, there exists a need for a thermal management system that is capable of meeting climate control requirements with increased efficiency.